#garfield Logs

Sep 15 2022

12:21 PM rue_mohr: in the end I got it
12:31 PM rue_mohr: it flashes the led
12:31 PM Tom_dev: i got mine also
12:31 PM Tom_dev: just gotta address the ssh right for it to work
12:31 PM polprog: gj rue_mohr !
12:55 PM rue_mohr: on the 6502, A is the only register you cant inc or dec hahahaha
12:58 PM rue_mohr: I need a script that sshs out to all my machines and runs ntpdate
03:00 PM aandrew: of course not, it's the accumulator. :-)
03:32 PM rue_mohr: hmm, my attempt to get the 6522 to output a square wave failed
04:26 PM polprog: oh wait rue_mohr what did you need with git?
04:26 PM polprog: i just noticed you pinged me up there
04:51 PM rue_mohr: tom was trying to work some things out
04:51 PM rue_mohr: I'm trying to work out why a 6522 wont output a square wave
04:52 PM rue_mohr: maybe I'll check the address bits, could I have mixed them up?
04:52 PM rue_mohr: I could lock it into an init loop and see what its doing
04:55 PM polprog: yeha make it run up thru all addresses see if the connections are right
04:55 PM polprog: you could use one of these old school LAs with loads of channels
04:59 PM polprog: there was one for $200 on local classified, a tek, with tri color CRT display
04:59 PM polprog: (the kinda with color LCD panel in front)
04:59 PM polprog: i kinda want it but i dont have the money nor much use for one
04:59 PM rue_mohr: the problem I'm having now would be explained if I got A2 and A3 mixed up on the 6522
05:00 PM rue_mohr: which I dont suspect I could have done, but its my only idea
05:00 PM polprog: beep beep
05:00 PM rue_mohr: I checked my code with every example I can find of operating the 6522 and its ok
05:01 PM rue_mohr: oh, you now what
05:01 PM rue_mohr: something is working
05:01 PM rue_mohr: because
05:01 PM rue_mohr: I'm flashing ALL the bits of port B
05:02 PM rue_mohr: and the bit that supposed to be controlled by the timer isn't doing ANYTHING
05:02 PM polprog: oops
05:03 PM rue_mohr: I wonder if the timer is shot in all my 6522s?
05:15 PM rue_mohr: waiiiiitttt.
05:15 PM rue_mohr: I think they tricked me
05:16 PM rue_mohr: ugh, the wording of this datasheet is awful
05:17 PM rue_mohr: in fact, it may not be necessary to write to the low order counter in some applications since the timing operation is triggered by writing to the high order latch
05:17 PM rue_mohr: ""
05:18 PM rue_mohr: so, to start the timer, you write to the high order latch?
05:19 PM rue_mohr: write to Timer 1 counter L
05:19 PM rue_mohr: :
05:20 PM rue_mohr: 8 bits loaded into the T1 low order latches, latch contents are transferred into the low order counter at the time the high order counter is loaded
05:20 PM rue_mohr: --
05:21 PM rue_mohr: so, when you write to the counter, your writing to the latch... so that when you write to the high order counter the low order latch is also transferred
05:21 PM rue_mohr: ?
05:22 PM rue_mohr: I think, I have to write to the COUNTER to make it start
05:22 PM rue_mohr: write to timer 1 counter H:
05:22 PM rue_mohr: " 8 bits loaded into T1 high order latches, also at this time both high and low order latches transffered into T1 counter. T1 interrupt flag is also reset"
05:23 PM rue_mohr: ...
05:23 PM rue_mohr: nothing here says "timing starts"
05:23 PM rue_mohr: but its implied by the clearing of the interrupt falg
05:44 PM rue_shop3: yes!
05:56 PM rue_mohr: bang on 600Hz the first time too!
09:18 PM Tom_L: rue_mohr, what is this 6522 beast you speak of for?
09:18 PM rue_mohr: its an IO chip for the 6502 cpu
09:19 PM Tom_L: what were the 6502 used in ?
09:20 PM rue_mohr: apple II
09:20 PM rue_mohr: and video games
09:20 PM rue_mohr: 1Mhz, but super cycle efficient
09:20 PM Tom_L: and what are your plans for it?
09:20 PM rue_mohr: (for its time)
09:20 PM rue_mohr: a 16 channel DC servo loop controller
09:21 PM Tom_L: my git problem was just cmd line syntax
09:21 PM rue_mohr: yes
09:21 PM rue_mohr: I didn't find my cheat sheet
09:22 PM Tom_L: it's pretty easy
09:22 PM Tom_L: you'd think they would give some sort of example but i never found one
09:23 PM rue_mohr: no I had to ask int eh irc channel
11:41 PM rue_mohr: ok, step 1 is to make a transmitter.